Why does AnalyticsListener.onAudioPositionAdvancing report playoutStartTimeMs relative to system clock instead of position?

I am comparing it to onPositionDiscontinuity in the sense that both are callbacks where EventTime may not be descriptive enough when it comes to positions.

onPositionDiscontinuity provides PositionInfo objects, however in order to know which position we advanced "from" in onAudioPositionAdvancing, the best that can be done (as far as I've been able to find) is using EventTime.currentPlaybackPositionMs. I find this both inconsistent with onPositionDiscontinuity (at least for implicit transitions) and problematic as said field seems to refer to the event time after having advanced audio position.

Is there a reason for this? Would it make more sense to go the onPositionDIscontinuity way and replace playoutStartTimeMs with a PositionInfo object describing the playout start position?